All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 earthquake · 2 km East of Longobucco (CS)

3 years ago · 22 Dec 2022, 02:56

A very light earthquake, probably not felt by people. Being deep, it is felt less at the surface.

Stronger than 82% of Italian events in the past year

Where

2 km East of LongobuccoEarthquakes in the province of CosenzaEarthquakes in Calabria

How far away could it be felt?

A quake this small is usually not felt by people: only seismographs record it.

Statistical estimate from the Italian intensity attenuation model (INGV): actual perception depends on geology, buildings and depth. Very shallow events can be felt locally even below the threshold.

Earthquake map

19 events
Magnitude:lightweakmoderatestrong

The energy released

How much energy this quake unleashed, translated into everyday comparisons.

7.6kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×63 its energy
M1this quakeM3

Each extra magnitude unit releases about 32 times more energy: an M5 is not "a bit stronger" than an M4 — it is a different league.

Energy estimated with the standard Gutenberg–Richter relation; an average lightning bolt ≈ 1 billion joules. Indicative values.

The race of the seismic waves

Two waves set off from the hypocentre: the faster P wave arrives first with a sharp jolt; the S wave carries the actual shaking.

P waves — the first sharp jolt (~6 km/s)S waves — the strongest shaking (~3.5 km/s)
t ≈ 20 s

Animation sped up ~4× compared to reality.

  • Corigliano-Rossano
    26 km from the epicentre
    first tremor in ~7 s
    main shaking in ~13 s
  • Cosenza
    37 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Crotone
    54 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Catanzaro
    62 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s

Theoretical times with average crustal speeds: real values vary with geology. The gap between P and S waves is what earthquake early-warning systems rely on.

How deep it was born

35 km
deep
4 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~18 km)

For the same magnitude, a shallow earthquake is felt much more than a deep one: the energy starts closer to the surface.

What kind of quake is this?

Foreshock

In hindsight it was a foreshock: 3 years ago the same area had a stronger quake (M2.4). This can only be said after the fact — it was not predictable beforehand.

2.4
The mainshock
4 km North of Longobucco
3 years ago · 22 Dec 2022, 05:04
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
14
last 30 days
10 before8 after
this quake
Strongest of the sequence2.4

How often does it happen here?

about every ~7 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 613 events in the last 12 years of the INGV catalogue.

An average computed on the recent past: it tells how used this area is to shaking, not when the next quake will come — earthquakes cannot be predicted.

The great earthquakes in this area's history

Almost a thousand years of catalogues: the strongest documented events within ~50 km.

16386.8
Crotonese earthquake
8 June 1638 · 24 km from here
XCompletely destructive: most buildings are destroyed.
11846.8
Valle del Crati earthquake
24 May 1184 · 39 km from here
IXDestructive: many buildings partly or fully collapse.
18326.7
Crotonese earthquake
8 March 1832 · 47 km from here
XCompletely destructive: most buildings are destroyed.
18546.3
Cosentino earthquake
12 February 1854 · 36 km from here
XCompletely destructive: most buildings are destroyed.

Source: Parametric Catalogue of Italian Earthquakes CPTI15 (INGV, CC BY 4.0).

The closest seismic structure

Cecita Lake

The epicentre lies about 8 km from Cecita Lake, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 1 and 15 km deep

Faults are mapped to build better and understand the territory: knowing them says nothing about when an earthquake will occur, which remains unpredictable. Source: DISS 3.3 (INGV, CC BY 4.0).

Other quakes in the area

1.3
3 years ago
22 Dec 2022, 02:57
1.8
3 years ago
22 Dec 2022, 03:03
1.3
6 km North of Longobucco
6 km North-West · 33 km
3 years ago
22 Dec 2022, 03:43
2.4
4 km North of Longobucco
5 km North-West · 29 km
3 years ago
22 Dec 2022, 05:04
0.7
5 km West of Acri
23 km West · 10 km
3 years ago
22 Dec 2022, 20:00
1.4
4 km West of Acri
22 km West · 15 km
3 years ago
22 Dec 2022, 20:14
1.3
3 years ago
18 Dec 2022, 12:50
1.4
8 km West of Paludi
12 km North · 27 km
3 years ago
17 Dec 2022, 12:10
1.6
6 km South-West of Acri
21 km West · 11 km
3 years ago
7 Dec 2022, 22:18
1.6
5 km South-West of Paludi
6 km North-East · 32 km
3 years ago
7 Dec 2022, 12:25

Data: INGV — National Institute of Geophysics and Volcanology (CC-BY 4.0)

Estimates computed by Meteare on INGV data (Gutenberg–Richter relation; Italian macroseismic intensity attenuation model).